空间光学遥感器长条形反射镜集成优化设计

针对空间光学遥感器离轴三反光学系统主镜的高轻量化率、高面形精度要求,提出了一种长条形反射镜集成优化的设计方法。首先利用变密度的拓扑优化方法分别得到刚度最大化和一阶频率最大化的反射镜拓扑模型,综合两种拓扑模型得到了反射镜的集成设计方案;然后提出了基于镜面变形值的镜体加强筋变量拓展优化方法,进行了设计变量的灵敏度分析,并对反射镜局部加强筋进行了多变量尺寸优化,得到了该长条形反射镜的最佳轻量化结构;最后对优化结果进行了有限元分析,仿真结果表明反射镜在优化后的面形精度有了显著提升,镜体质量仅为8.65 kg,与实心镜体相比轻量化率达到了80.9%。在Z向1g重力作用下,镜面面形精度峰谷值为23.70 nm,均方根值为4.54 nm,该优化方法能很好地满足设计要求。

Integrated Design of Rectangular Mirror for Space Optical Remote Sensor

An integrated optimization design method for rectangular mirror was applied in this paper aiming at the requirements of high lightweight ratio and high surface figure quality of the primary mirror in off-axis three-mirror optical system for space optical remote sensor. Firstly, the topology optimization method with variable density was used to obtain the mirror topology models with maximum stiffness and maximum first-order frequency respectively, the integrated design scheme of the mirror was obtained by synthesizing the two topology models. Then, a variable expansion optimization method of the mirror ribs based on the mirror deformation value was proposed, the sensitivity analysis of the design variables was carried out, and the multi-variable size optimization of the local ribs of the mirror was optimized, Finally, the optimization result was analyzed by finite element method. The result of finite element simulation analysis shows that the surface figure of the mirror after optimization has been significantly improved. The weight of the mirror after size optimization design is only 8.65 kg, resulted in a weight reduction of about 80.9% compared to the initial solid mirror. Under the loading condition of 1 G gravity in Z direction, The PV value is 23.70 nm, with RMS is 4.54 nm. which meets the design requirements.